1 literature reference for Cottus gobio koshewnikowi (non Gratzianov, 1907):

Author: Freyhof, J., M. Kottelat and A. Nolte
Year: 2005
Title: Taxonomic diversity of European Cottus with description of eight new species (Teleostei: Cottidae).
Source: Ichthyol. Explor. Freshwat. 16(2):107-172.